CN114172182A

CN114172182A - Electric automobile bidirectional charging and discharging system and method and electric automobile

Info

Publication number: CN114172182A
Application number: CN202111476983.2A
Authority: CN
Inventors: 张振海; 张振山
Original assignee: Beijing Haitai Weina Technology Development Co ltd
Current assignee: Beijing Haitai Weina Technology Development Co ltd
Priority date: 2021-12-06
Filing date: 2021-12-06
Publication date: 2022-03-11
Anticipated expiration: 2041-12-06
Also published as: CN114172182B

Abstract

The invention belongs to the field of electric automobiles, and particularly relates to a bidirectional charging and discharging system and method for an electric automobile and the electric automobile, wherein the bidirectional charging and discharging system comprises: the vehicle-mounted slow charging socket end and the vehicle-mounted control module; the vehicle-mounted slow charging socket end is connected with an automobile bus, so that the vehicle-mounted control module receives and transmits a control command through the vehicle-mounted slow charging socket end and controls the charging process or the discharging process of the battery unit. Through being connected on-vehicle slow charging socket end and car bus, as communication interface for on-vehicle slow charging socket end has communication function, thereby can communicate with the control end, realizes receiving control command and carries out two-way charge-discharge, and abundant regard electric automobile as decentralized electrochemistry energy storage resource utilization.

Description

Electric automobile bidirectional charging and discharging system and method and electric automobile

Technical Field

The invention belongs to the technical field of new energy, and particularly relates to a bidirectional charging and discharging system and method for an electric automobile and the electric automobile.

Background

Since 2008, the energy consumption of China is always at the first position in the world, and in 2019, the primary energy consumption of China reaches 1417 trillion joules, which is 1.5 times of the secondary energy consumption of the second United states, 1.7 times of the European energy consumption, and is the sum of the remaining ten countries before the global primary energy consumption.

In 2020, the oil consumption of China reaches 7.02 hundred million tons, and rises by 35 percent compared with 2014, meanwhile, the import quantity also rises by 50 to 5.42 hundred million tons, and the external dependence degree is 77.21 percent. The natural gas consumption is 3250 billion cubic meters in 2020, the gas consumption rises by 72.8% in 2014, the gas import rises by 135% to 1414 billion cubic meters at the same time, and the external dependence rises from 31.9% to 43.49%.

The new energy automobile is vigorously developed, the photovoltaic power and the wind power are developed, and the method has remarkable significance for guaranteeing the energy safety of 14 hundred million population countries and reducing the external dependence. It is not important whether the scientific basis for the influence of greenhouse gas emissions on the world climate stands.

The installed capacity of power generation in the whole country at the end of 2021 is 22.8 hundred million kilowatts, wherein the installed capacity of power generation by renewable energy sources breaks through 10 hundred million kilowatts. Photovoltaic and wind power are still the most realistic power and the largest growth point for implementing the double-carbon policy for a while, but the defects of the photovoltaic and wind power are instable, so that the demand on an energy storage power station is huge. Long term development planning for pumped storage in middle and old (2021-2035) published by the State energy agency requires acceleration of the approval construction of pumped storage power stations.

With the rapid popularization of electric vehicles, electric vehicles are receiving more and more attention as dispersed electrochemical energy storage resources.

In the year 2021, in 5 months, all the units of the dunghed pumped storage power station generate electricity, the installed capacity is 140 kilowatts, the pumped electricity is used for 32 hundred million kilowatt hours every year, the electricity is generated for 25 hundred million kilowatt hours every year, and the efficiency is 75 percent. The energy can be stored for 894 ten thousand degrees and supplied for 688 ten thousand degrees in average every day.

The charging and discharging efficiency of the electric automobile is as high as 90%. If an average available free capacity per vehicle is 35 degrees, discharging 30 degrees, then about 20 ten thousand vehicles are needed to achieve a discharge capacity of 688 ten thousand degrees.

Nearly 10 million new energy automobiles are added in Shanghai every year, and the total number of the automobiles is more than 400 million; more than 6 million new energy automobiles are added to Beijing every year, and the total amount of automobile reserves is more than 600 ten thousand. Therefore, according to the development speed of the current new energy automobiles, about 20 million new energy automobiles newly added in 2-3 years in Beijing and Shanghai are equivalent to the construction of a dunning scale pumped storage power station if being used, the construction period of the pumped storage power station is 5-6 years, and the total investment reaches 78 hundred million yuan.

Therefore, the distributed electrochemical energy storage power station based on the on-grid electric automobile becomes important power which is not negligible.

The current electric automobile is generally provided with two charging interfaces: slow charging and quick charging.

The slow charging is alternating current and is controlled by a vehicle-mounted charger, and at present, the slow charging can only be carried out and can not be discharged to a power grid; the quick charging is direct current, and the battery pack is directly charged by the off-board charger.

However, most of the existing schemes utilize a quick charging interface, and an off-board charger finishes electric energy feedback to a power grid, namely a direct current charging pile finishes the electric energy feedback.

The direct current fills electric pile system complicacy, and power is very big, generally distributes in places such as large-scale parking area, highway service area at present, and the quantity is less, also generally fills soon and walks away, can not be on the net for a long time, even fill electric pile and have the function of repayment electric wire netting, the car has few chances to repayment electric energy to the electric wire netting. In addition, even if the power of the off-board charger contained in the quick charging device is reduced to be as small as that of slow charging, the price of the off-board charger is far higher than that of a contactor in the slow charging device, so that the off-board charger is difficult to popularize; if an off-board inverter is added that returns power to the grid, the cost is higher.

Compared with the prior art, the alternating-current charging pile is convenient for to install in a large number because of low price, no matter at home or in work units or public parking lots, if everywhere has, just can park and insert promptly, makes the electric motor car become very huge at the net number volume, becomes the considerable electrochemistry energy storage resource of scale.

However, the current slow charging interface has no channel for receiving a power grid dispatching instruction; the current vehicle-mounted charger of the electric automobile generally has no function of inverting and returning to a power grid; if the wired communication interface and the vehicle-mounted inverse transformation power grid part are changed, the compatibility problem with the existing charging pile and the existing old electric vehicle is also considered.

Based on this, how to design out and receive electric wire netting scheduling instruction through the interface that slowly fills and carry out two-way charge-discharge system and method, the idle energy of the electric automobile battery that can the rapid development of make full use of can promote a low-priced alternating-current charging stake again rapidly, make more electric automobile convenient long-time online charge-discharge, can compatible existing electric pile and electric automobile again, safe charging is the problem that awaits a urgent solution.

Disclosure of Invention

In order to solve the problems that in the prior art, a communication channel is not arranged at a slow charging interface of an electric automobile, a battery on the electric automobile cannot be used as an electrochemical energy storage resource to receive a control instruction, and the battery is charged from a power grid or discharged to the power grid according to a power grid scheduling instruction so as to assist photovoltaic and wind power development, the embodiment of the invention provides the following technical scheme:

in a first aspect, the present application provides a bidirectional charging and discharging system for an electric vehicle, the bidirectional charging and discharging system comprising:

the vehicle-mounted slow charging socket end and the vehicle-mounted control module;

the vehicle-mounted slow charging socket end is connected with an automobile bus, so that the vehicle-mounted control module receives and transmits a control command through the vehicle-mounted slow charging socket end and controls the charging process or the discharging process of the battery unit.

Furthermore, the vehicle-mounted slow charging socket end is provided with a first wiring port and a second wiring port, and the first wiring port and the second wiring port are respectively connected with two signal lines of an automobile bus.

The first wiring port and the second wiring port are connected with two signal lines of an automobile bus through the converter.

Further, the on-board control module includes: the vehicle-mounted discharging control unit is connected with the vehicle-mounted discharging unit and used for receiving the control command and controlling the vehicle-mounted discharging unit to discharge to the battery unit.

Further, the on-board control module includes: the vehicle-mounted charging control unit is connected with the vehicle-mounted charging unit and used for receiving the control command and controlling the vehicle-mounted charging unit to charge the battery unit.

Further, the vehicle-mounted slow charging socket end comprises a first photoelectric isolation module and a second photoelectric isolation module;

the first optoelectronic isolation module includes: a light guide plate and a light emitting diode; the light guide sheet is matched with the light emitting diode to convert the electric signal into an optical signal and lead out along the light guide sheet;

the second photoelectric isolation module comprises a light guide sheet and a photodiode; the light guide sheet is matched with the photodiode to convert the light guided by the light guide sheet into an electric signal.

Further, the charging and discharging control module further comprises a vehicle controller and an anti-theft unit, wherein the anti-theft unit is connected with the vehicle controller and is used for setting or modifying a user name and a password so as to prevent electricity stealing.

The battery management system further comprises a BMS module, wherein the BMS module is respectively connected with the battery unit and the vehicle-mounted slow charging socket end, and is used for detecting the battery state of the battery unit and sending a state signal through the vehicle-mounted slow charging socket end;

the BMS module is provided with a battery wear recording unit and an inquiry unit;

the battery wear recording unit is used for acquiring and storing battery temperature information, voltage information and current information, and performing data processing and storage;

the query unit is connected with the battery wear recording unit and used for querying the charging electric quantity and the discharging electric quantity of the battery in any time interval and querying the charging and discharging times of any voltage interval of the battery.

In a second aspect, the present invention provides a bidirectional charging and discharging method for an electric vehicle, including:

acquiring a user name and a password, and verifying the user name and the password to obtain a verification result;

if the verification result is that the verification is passed, receiving a control instruction, wherein the control instruction comprises a specified charging and discharging current value and electric quantity;

detecting the current value and the total electric quantity of the acceptable charge and discharge quantity of the battery unit according to the control instruction;

judging the specified charge-discharge current value and the total electric quantity, and obtaining a judgment result together with the charge-discharge current value and the total electric quantity received by the battery unit;

and controlling the charging process or the discharging process of the battery unit according to the judgment result, and reporting abnormal state information.

In a third aspect, the present invention provides an electric vehicle including the bidirectional charge and discharge system according to any one of the first aspect.

The invention has the following beneficial effects:

the embodiment of the invention provides a bidirectional charging and discharging system of an electric automobile, which comprises: the vehicle-mounted slow charging socket end and the vehicle-mounted control module; the vehicle-mounted slow charging socket end is connected with an automobile bus, so that the vehicle-mounted control module receives and transmits a control command through the vehicle-mounted slow charging socket end and controls the charging process or the discharging process of the battery unit. Through being connected on-vehicle slow charging socket end and car bus, as communication interface for on-vehicle slow charging socket end has communication function, thereby can communicate with the control end, realizes receiving control command and carries out two-way charge-discharge, and abundant regard electric automobile as decentralized electrochemistry energy storage resource utilization.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic diagram of a structure of a bidirectional charging and discharging system of an electric vehicle according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of a signal isolation transformer according to an embodiment of the present invention.

Fig. 3 is a schematic diagram of a converter according to another embodiment of the present invention.

Fig. 4 is a schematic diagram of a photoelectric isolation according to another embodiment of the present invention.

Fig. 5 is a data reference diagram for metering charging according to an embodiment of the present invention.

Fig. 6 is a schematic diagram of voltage and current traces of a battery provided by an embodiment of the present invention.

Fig. 7 is a graph illustrating a charge-discharge gradient of a battery according to an embodiment of the present invention.

Fig. 8 is a schematic flow chart of a bidirectional charging and discharging method for an electric vehicle according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the examples given herein without any inventive step, are within the scope of the present invention.

Aiming at the problem that the conventional electric automobile can only be charged from a power grid as a load and cannot be used as an electrochemical energy storage resource to receive a power grid dispatching instruction, and is charged from the power grid or discharged to the power grid according to the power grid dispatching instruction to assist photovoltaic and wind power development, the embodiment of the invention provides a system and a method for realizing charging and discharging of the electric automobile and the electric automobile.

Referring to fig. 1, fig. 1 is a schematic diagram illustrating a structure of a bidirectional charging and discharging system of an electric vehicle according to an embodiment of the present invention, and as shown in fig. 1, the bidirectional charging and discharging system includes:

the vehicle-mounted slow charging socket comprises a vehicle-mounted slow charging socket end 1 and a vehicle-mounted control module 2;

the vehicle-mounted slow charging socket end 1 is connected with an automobile bus 3, so that the vehicle-mounted control module 2 receives and transmits a control instruction through the vehicle-mounted slow charging socket end 1 and controls the charging process or the discharging process of the battery unit.

As a further improvement of the above system, in an embodiment, the vehicle-mounted slow charging socket end is provided with a first connection port and a second connection port, and the first connection port and the second connection port are respectively connected with two signal lines of an automobile bus.

It should be noted that the key point of the invention is to change the national standard slow charging interface, and use two idle terminals, i.e. L2 and L3, which are originally defined as strong current terminals but are not used in practice, as weak current communication interfaces, so that the wired communication between the electric automobile and the slow charging pile is possible.

The charging and discharging between the electric automobile and the power grid need to be carried out by the electric automobile and the power grid dispatching center, the charging and discharging process needs to be completed through the charging pile, a wireless interface mode is adopted for communication in the prior art, compared with wireless communication, wired communication is more stable, but a channel for carrying out communication through a slow charging interface is not available at present.

In the existing electric automobile, a charging socket comprises a slow charging interface end and a fast charging interface end, wherein the slow charging interface end is alternating current and is controlled by a vehicle-mounted charger, so that charging can be carried out only at present, and discharging to a power grid cannot be carried out; the quick charging interface end is direct current, and the battery pack is directly charged by the non-vehicle-mounted charger. The quick charging socket end is provided with S + and S-terminals with bus communication functions, and the simplest implementation mode of the implementation of the invention is that a pair of two idle terminals, namely a first wiring port and a second wiring port, in the vehicle-mounted slow charging socket end and two bus communication terminals in the vehicle-mounted quick charging socket end are directly connected. Therefore, the vehicle-mounted slow charging socket end has a bus communication function, and bidirectional flow of electric energy according to a scheduling instruction can be realized by receiving and sending a control instruction through a bus.

The first interface and the second interface are that the L2 and L3 terminals in the national standard slow charging socket are directly connected with the S + and S-terminals in the national standard fast charging socket in a pair through the L2 and L3 terminals, so that the L2 and L3 terminals are directly connected to an automobile bus, and bus communication is carried out through the slow charging socket interface. Because all modules on the automobile are connected to the bus, authentication of authorization information such as user names and passwords can be achieved through the L2 and 3 terminals of the slow charging interface, instructions such as charging current and generating current are issued to the control module, and setting information of the automobile owner on the capacity of the residual battery and information such as real-time temperature of the battery can also be read.

Certainly, in order to make electric automobile can communicate with the plug end of filling slowly of filling electric pile through filling the interface slowly, in this embodiment, still need improve filling electric pile, be about to fill two idle terminals of electric pile alternating current charging plug end and be connected with the controller, like this, with the electric automobile's that improves fill slowly interface and the modified alternating current charging plug end of filling electric pile and be connected, can communicate.

In another embodiment, the invention considers another embodiment mode for safety reasons, because in the existing national standard, L2 and L3 are not weak electric communication terminals but strong electric power, and are the other two phases of a three-phase power supply, and the phase voltage is 380V. Although the current slow charging pile only uses single-phase alternating current, namely 220V is between L1 and N, and L2 and L3 are idle terminals, in case that manufacturers develop the slow charging pile according to national standards, introduce three-phase alternating current, and use L2 and L3, the converter, the bus and related circuits in the above embodiment are likely to be burnt out to affect the use of the vehicle. In order to avoid such accidents, signal transformer isolation can be adopted on the communication interface of the converter, as shown in fig. 2, fig. 2 is a schematic diagram of the conversion of the signal isolation transformer provided by an embodiment of the present invention, L2 and L3 at the slow charging socket end pass through the signal isolation transformer and are connected to S + and S-of the fast charging socket, which has the advantage that even if L2 and L3 are connected to 380V, only the primary side of the transformer is burned, i.e. at the slow charging socket side, the bus of the vehicle cannot be damaged, and the vehicle-mounted control module cannot be damaged. After the interface is damaged, although the charging and discharging can not be carried out according to the dispatching instruction of the power grid, the charging can still be normally carried out, and the vehicle-using of the vehicle owner is not influenced.

Referring to fig. 3, fig. 3 is a schematic diagram of a converter according to another embodiment of the present invention, which further includes a converter, which can be implemented by a single chip, and the first wire connection port and the second wire connection port are connected to two signal lines of an automobile bus through the converter.

Because the bus communication protocol is relatively complicated, one end of the converter is connected with the L2 and the L3 at the end of the vehicle-mounted slow charging socket, the other end of the converter is connected with the S + and the S-of the bus, the converter reads information such as battery temperature from a battery management system BMS through bus communication and converts the information into an RS232 interface through interface conversion, for example, so that the L2 and the L3 can conveniently realize full duplex communication of one receiving and one transmitting.

Referring to fig. 4, fig. 4 is a schematic diagram of a photoelectric isolation according to another embodiment of the present invention, in order to further enhance protection of a communication interface, the present invention provides a protection manner using the photoelectric isolation, and as shown in fig. 4, the vehicle-mounted slow charging socket includes a first photoelectric isolation module and a second photoelectric isolation module; the first optoelectronic isolation module includes: a light guide plate and a light emitting diode; the light guide sheet is matched with the light emitting diode to convert the electric signal into an optical signal and lead out along the light guide sheet; the second photoelectric isolation module comprises a light guide sheet and a photodiode; the light guide sheet is matched with the photodiode to convert the light guided by the light guide sheet into an electric signal.

It can be understood that the light guide plate of L2 receives light from the light emitting diode in the plug and transmitted through the light guide column, and is converted into an electrical signal by the photodiode; the led of L3 converts electrical signals to optical signals, which are converted to electrical signals by the photodiode via the light guide plate and the light guide post on the plug side. The light guide plate and the light guide column are made of transparent insulating materials, and strong electricity cannot be introduced, so that the light guide plate is very safe, and even if someone intentionally introduces strong electricity to destroy, the interface cannot be burnt. Another beneficial effect is that the identifiability is strong, and leaded light piece and metal binding post difference are huge, if adopt visible light, like ruddiness transmission signal, the identifiability is just stronger, observes the interface through the naked eye, just judges very easily whether can be to the electric motor car or fill electric pile that the electric wire netting provided the electric energy.

In one embodiment, the onboard control module includes: the vehicle-mounted discharging control unit is connected with the vehicle-mounted discharging unit and used for receiving the control command and controlling the vehicle-mounted discharging unit to discharge to the battery unit.

That is, after the vehicle-mounted discharge control unit receives the control command for discharging the battery unit, the electric vehicle controls the vehicle-mounted discharge unit to discharge with the battery unit.

In one embodiment, the onboard control module includes: the vehicle-mounted charging control unit is connected with the vehicle-mounted charging unit and used for receiving the control command and controlling the vehicle-mounted charging unit to charge the battery unit.

After the vehicle-mounted charging control unit receives a control instruction for charging the battery unit, the electric vehicle controls the vehicle-mounted charging unit and the battery unit to charge.

In practical use, the technical scheme provided by the invention can be that the vehicle-mounted discharging control unit, the vehicle-mounted discharging unit, the vehicle-mounted charging control unit and the vehicle-mounted charging unit are taken as an integral module, even if the vehicle-mounted discharging control unit is used by the vehicle-mounted control module, the vehicle-mounted discharging control unit and the vehicle-mounted discharging unit can be taken as independent vehicle-mounted discharging modules, and the vehicle-mounted charging control unit and the vehicle-mounted charging unit can be taken as an independent vehicle-mounted charging module.

As a further improvement of the above embodiment, in an embodiment, the charging and discharging control module further includes a vehicle controller and an anti-theft unit, and the anti-theft unit is connected with the vehicle controller and used for setting or modifying a user name and a password to prevent electricity stealing.

The gasoline tank of the gasoline vehicle has the consideration of preventing oil theft in structural design, such as locking, for example, the oil inlet has a bent design for preventing the insertion pipe, and the like. However, in the existing electric automobile, as long as a discharging gun device is bought from Taobao and plugged into a quick charging socket, high-voltage direct current of a battery can be obtained and converted into a standard alternating current power supply of 220V/50Hz, and other automobiles can be charged or connected with high-power electric appliances such as an induction cooker and the like.

The charging and discharging control module further comprises a vehicle controller and an anti-theft unit, the anti-theft unit is connected with the vehicle controller, the anti-theft unit comprises an anti-theft related program and a touch screen on an automobile or a mobile phone APP and other human-computer interface equipment connected to an automobile local area network, and a user can set or modify a user name and a password through the human-computer interface equipment. After the anti-theft unit function is started, the contactor on the direct current bus in the automobile cannot be automatically switched on after the quick charging interface is inserted into the charging and discharging gun. If the battery is to be connected, the battery needs to be communicated through an S + bus and an S-bus, a correct user and a correct password are provided, the contactor can be connected only by sending an instruction after the battery passes the authentication, and the high-voltage direct current of the battery can be generated on the quick charging interface. In addition, an option of whether the anti-theft unit is started or not needs to be set, otherwise, the current quick charging pile cannot charge the automobile. The anti-theft unit is not only used for the quick charging interface, but also used for the slow charging interface. On the automobile touch screen or the mobile phone is connected to the automobile local area network, namely in a local mode, a user can operate the slow charging interface to output 220V standard alternating current or other grade power supplies; however, if the vehicle is required to discharge to the outside through the slow charging interface, namely, the remote mode, the authentication of the user name and the password is required to prevent the illegal use of the electric energy in the vehicle battery.

As a further improvement of the above embodiment, in one embodiment, the battery management system further comprises a BMS module connected to the battery unit and the vehicle-mounted slow charging socket terminal, respectively, for detecting a battery state of the battery unit and transmitting an abnormal state signal through the vehicle-mounted slow charging socket terminal;

the abnormal state comprises the conditions of charging and discharging temperature abnormity, current and voltage abnormity, frequency abnormity, sudden disconnection of a charging and discharging interface and the like.

When the method is specifically implemented, the user can more fully know the battery of the electric automobile, namely the historical condition of the battery and the balance condition of the battery asset operation. The specific implementation method is that a BMS module is provided with a battery wear recording unit and an inquiry unit;

first, the voltage and current curves of the battery are recorded by the battery wear recording unit, which is easily done today when the storage cost is continuously reduced, for example, one pair of voltage and current values per second, or 10 pairs per second, is also possible. And multiplying the voltage by the current to obtain electric power, integrating the electric power to obtain electric quantity after determining the starting time and the ending time, integrating the positive electric power to obtain discharge electric quantity, and integrating the negative electric power to obtain charge electric quantity.

Further, the driving discharge amount and the braking charge amount, and the charging amount and the discharging amount between the driving discharge amount and the braking charge amount and the power grid can be counted respectively, as shown in fig. 5, fig. 5 is a data reference diagram for metering and charging provided by an embodiment of the present invention, and as the electricity price changes in time intervals, the real-time electricity price of the power grid is obtained, and the balance and balance condition can be calculated.

As shown in fig. 6, fig. 6 is a schematic diagram of voltage and current traces of a battery according to an embodiment of the present invention, where fig. 6 is a diagram obtained by plotting each pair of voltage and current on a two-dimensional plane graph, where one coordinate axis is voltage and the other is current. Thus, the voltage and voltage curve is a trace on the graph. In the figure, a solid line is schematic of a charging and discharging track of a travelling crane, and a dotted line is schematic of a charging and discharging track between the travelling crane and a power grid. The track is composed of a point, and the coordinates of the point are the collected and recorded voltage and current.

Furthermore, the voltage and current coordinate plane is divided into fine grids, the number of times that each grid is crossed by the voltage and current tracks is counted, the number of times is graded and is represented by different colors or gray levels, and then the wear condition of the battery can be displayed more finely by a gradient map. Fig. 7 is a graph illustrating a charge-discharge gradient of a battery according to an embodiment of the present invention. As shown in fig. 7, the number of times of charge and discharge is obtained by adding the numbers of times in the respective small grids having the same voltage value. Excessive temperatures may damage the battery or affect its life, so the battery temperature should also be collected and stored, especially for periods of excessive or insufficient temperature.

Referring to fig. 8, fig. 8 is a schematic flow chart illustrating a bidirectional charging and discharging method for an electric vehicle according to an embodiment of the present invention, as shown in fig. 8, the bidirectional charging and discharging method for an electric vehicle includes the following steps:

step S801, obtaining a user name and a password, and verifying the user name and the password to obtain a verification result

Step S802, if the verification result is that the verification is passed, receiving a control instruction, wherein the control instruction comprises a specified charge-discharge current value and an electric quantity;

step S803, detecting the acceptable charge and discharge current value and the total electric quantity of the battery unit according to the control instruction;

step S804, judging the charge and discharge current value and the total electric quantity appointed by the power grid and the charge and discharge current value and the total electric quantity accepted by the battery unit to obtain a judgment result;

and step S805, controlling the charging process or the discharging process of the battery unit according to the judgment result, and reporting abnormal state information.

In one embodiment, the electric vehicle obtains a user name and a password through a slow charging socket end, verifies the user name and the password to obtain a verification result, and receives a control instruction if the verification result is correct, wherein the control instruction comprises a charging and discharging current value and a total electric quantity specified by a power grid; after receiving the control instruction, detecting the acceptable charge and discharge current value and the total electric quantity of the battery unit according to the control instruction; that is, the electric quantity which can be used for discharging or the remaining electric quantity which must be reserved of the electric vehicle of the user and the maximum current value which can be allowed are set by the user, and then the charge-discharge current value and the total electric quantity which are specified by the power grid and the charge-discharge current value and the total electric quantity which are accepted by the battery unit are judged to obtain a judgment result;

if the judgment result is that the specified charging and discharging current value of the power grid is larger than the acceptable charging and discharging current value of the battery unit, discharging to the power grid according to the current value of the battery unit;

and if the judgment result is that the specified charging and discharging current value of the power grid is small and the acceptable charging and discharging current value of the battery unit is obtained, the battery unit discharges to the power grid by the specified charging and discharging current of the power grid.

For example, in actual use, when the charging and discharging current value specified by the power grid is received to be 10A, and the user of the electric vehicle sets the charging and discharging current acceptable to the battery unit to be 5A, the battery unit is charged and discharged to the power grid at the current of 5A, and the situation is reported so as to adjust the scheduling. Similarly, if the user sets the acceptable charging and discharging current of the battery unit to be 15A, the battery unit is charged and discharged to the power grid at the current of 10A.

And if the judgment result is that the specified total charge and discharge amount of the power grid is larger than the acceptable total charge and discharge amount of the battery unit, charging and discharging the power grid according to the acceptable total charge and discharge amount of the battery unit.

And if the judgment result is that the total charge and discharge amount specified by the power grid is smaller than the acceptable total charge and discharge amount of the battery unit, charging and discharging the battery unit to the power grid according to the total charge and discharge amount specified by the power grid.

For example, in actual use, when the total charge and discharge capacity specified by the power grid is received to be 50KWh, and the total charge and discharge capacity acceptable for the battery unit is set to be 10KWh by the user of the electric vehicle, the total charge supplied to the power grid is stopped when the total charge reaches 10KWh, and the situation is reported as early as possible so as to adjust the scheduling. The purpose of this rule is not only to prevent the battery from being overcharged or overdischarged, but also to reserve enough electric quantity according to the requirement of the user to prevent the influence on normal use of the vehicle. Similarly, if the total charge/discharge acceptable for the battery cell is 70KWh, the user can charge/discharge the battery to the grid to 50 KWh. The remaining quota is also reported for scheduling adjustments to increase revenue and make full use of idle battery resources.

The electric automobile receives the user name and the password through the slow charging socket terminal, and if the user name and the password are incorrect, the electric automobile cannot discharge electricity to prevent electricity stealing.

As a further improvement of the embodiments on the market, the invention also provides an electric vehicle comprising the bidirectional charge and discharge system as described in any one of the above.

It is understood that the same or similar parts in the above embodiments may be mutually referred to, and the same or similar parts in other embodiments may be referred to for the content which is not described in detail in some embodiments.

It should be noted that, in the description of the present application, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Further, in the description of the present application, the meaning of "a plurality" means at least two unless otherwise specified.

Any process or method descriptions in flow charts or otherwise described herein may be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps of the process, and the scope of the preferred embodiments of the present application includes other implementations in which functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those reasonably skilled in the art of the present application.

It should be understood that portions of the present application may be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, the various steps or methods may be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any one or combination of the following techniques, which are known in the art, may be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application specific integrated circuit having an appropriate combinational logic gate circuit, a Programmable Gate Array (PGA), a Field Programmable Gate Array (FPGA), or the like.

It will be understood by those skilled in the art that all or part of the steps carried by the method for implementing the above embodiments may be implemented by hardware related to instructions of a program, which may be stored in a computer readable storage medium, and when the program is executed, the program includes one or a combination of the steps of the method embodiments.

In addition, functional units in the embodiments of the present application may be integrated into one processing module, or each unit may exist alone physically, or two or more units are integrated into one module. The integrated module can be realized in a hardware mode, and can also be realized in a software functional module mode. The integrated module, if implemented in the form of a software functional module and sold or used as a stand-alone product, may also be stored in a computer readable storage medium.

The storage medium mentioned above may be a read-only memory, a magnetic or optical disk, etc.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example" or "some examples" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although embodiments of the present application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present application, and that variations, modifications, substitutions and alterations may be made to the above embodiments by those of ordinary skill in the art within the scope of the present application.

Claims

1. The utility model provides a two-way charge-discharge system of electric automobile which characterized in that, two-way charge-discharge system includes:

2. The bidirectional charging and discharging system according to claim 1, wherein the vehicle-mounted slow charging socket end is provided with a first wiring port and a second wiring port, and the first wiring port and the second wiring port are respectively connected with two signal lines of an automobile bus.

3. The bidirectional charge and discharge system according to claim 2, further comprising a converter, wherein the first wiring port and the second wiring port are connected to two signal lines of an automobile bus through the converter.

4. The bidirectional charge-discharge system according to claim 1, wherein the vehicle-mounted control module includes: the vehicle-mounted discharging control unit is connected with the vehicle-mounted discharging unit and used for receiving the control command and controlling the vehicle-mounted discharging unit to discharge to the battery unit.

5. The bidirectional charge-discharge system according to claim 1, wherein the vehicle-mounted control module includes: the vehicle-mounted charging control unit is connected with the vehicle-mounted charging unit and used for receiving the control command and controlling the vehicle-mounted charging unit to charge the battery unit.

6. The system according to claim 1, wherein the vehicle-mounted slow charging socket end comprises a first photoelectric isolation module and a second photoelectric isolation module;

7. The bidirectional charging and discharging system according to claim 1, wherein the charging and discharging control module further comprises a vehicle controller and an antitheft unit, and the antitheft unit is connected with the vehicle controller and is used for setting and modifying a user name and a password so as to prevent electricity stealing.

8. The bi-directional charging and discharging system according to claim 1, further comprising a BMS module connected to the battery unit and the vehicle-mounted slow charging socket terminal, respectively, the BMS module being configured to detect a battery state of the battery unit and to transmit a state signal through the vehicle-mounted slow charging socket terminal;

9. A bidirectional charging and discharging method for an electric automobile is characterized by comprising the following steps:

if the verification result is that the verification is passed, receiving a control instruction, wherein the control instruction comprises a specified charging and discharging current value and a total electric quantity;

judging the magnitude of the charge and discharge current value appointed by the power grid and the charge and discharge current value accepted by the battery unit to obtain a judgment result;

10. An electric vehicle characterized by comprising the bidirectional charge and discharge system according to any one of claims 1 to 8.